The three locations in red:


/

 

Just on a side note while we're trying to figure this out, how much do ya'll reckon we could get out of this truck if we have to sell? We are moving first week of May, and can't leave it here so we will have to sell if we don't get it fixed within the next couple weeks. It's a 1992 F150 5.8l 351 4x4 with 228k miles. 4" bds suspension lift with 33s BFG all terrains. Dual exhaust with glass packs put in a couple years ago. Reman transmission put in last year, replaced transfer case as well. The door latch is broken on the driver's side, and probably needs the dash replaced. No rust. But in a non driveable condition, how much you reckon we could squeeze out of it? I love this truck to death but life happens. I have no idea what to even ask for it since it won't run well.

 

We did a compression test tonight. Are these too low? Haynes Manuel says lowest cylinder must be at least 75% of highest cylinder. Which it is.
Results:
Cylinder #1 = 80psi
#2=90 psi
3=90
4=85
5=85
6=80
7=80
8=90

 

Okay, so once we put all the plugs and wires back on, we started it up and it ran okay. Let it sit for a little bit, then tried putting it in drive and it died. So we decided to just try a different MAP sensor, now it won't start up again. We put the original MAP sensor back on, still no start.

Would it be a good idea to test the fuel injectors next?

 

You say you still have fuel pressure when it dies and it sounds like it will start and run OK when cold but not if it had ran and got warm.
This could only be the Ignition Coil, ICM, PCM or the PIP sensor.
I know without rereading your thread that you have replaced some of these parts.

You need to put a NOID light on it when it does not start, you can rent them from most auto part stores and get your money back when you bring them back.
You also need to check for spark when it does not start with a spark tester, they are very low cost.

 

We've replaced the PCM, but none of the others. Checked coil for spark, but engine was cold at the time. Is there a way to test those other than just replacing? I guess we need to get out there tomorrow and start it up so it can warm up and we can check for spark when it doesn't start again. But it definitely is looking related to the engine warming up.

 

Gee Whiz buddy, have you read post #17 above in your thread?

 

No sir, I'm sorry, I didn't see that. Thanks, we'll try it

 

sgoodman95: You may want to take a look at my experience following Abraham's methodical troubleshooting approach here for an example:

https://www.ford-trucks.com/forums/1...l#post17086763

From my reading electrical problems are hard to diagnose properly but very quick to fix, while mechanical problems are easy to diagnose and are slow to repair. It requires a different mindset. But if you commit yourself to follow the troubleshooting steps without cutting corners, you will find the problem. Take a look at all of Abraham's troubleshooting approaches for your particular engine here:

Ford Main Index Of Tutorials

 

I have a 95 F150 with the same engine and mileage. I have been reading this and went through the same no start issue about 2 months ago. Changed coil, checked ignition module, pcm, etc. All the things you have done. When I checked the engine coolant temperature sensor, it came apart when I tried to unplug the wires. Replaced it and the problem went away.

 

is that what they call the ECT?

 

Yes it is called the ECT (engine coolant temperature sensor).
And it has nothing to do with the working of the temp gauge in the dash.
This ECT sensor has two wires to it where the Temp sender for the dash gauge has one push on wire.

 

Well we're gonna test the ACT, ECT, and ICM tonight. So hopefully it'll be one of those!

 

If the BAD ECT always tells the PCM Computer it is cold then the PCM provide a rich fuse/air mixture for it to start. Then the engine will start cold. Then when the engine is warm the BAD ECT will still be telling the PCM that the engine is cold and the engine will run bad and will not restart until it cools off with the rich fuse/air mixture.

Also a BAD ECT sensor may not give a code as the PCM does not know the ECT is lying to it.

This also goes for the ACT sensor to some degree.

 

Great news! We replaced the thermostat, because we realized it was staying closed. And also replaced the ECT and ACT. We started it today and left it running for a while so it could get warmed up, then shut it off and started it five times in a row. No issues! Put it in drive, pulled it forward. Same with reverse. No shut off! It seems to not have the power it should, but it was a high idle so I'm not sure if that's why. But this is a huge step. I'm gonna start it again later when I get home and see how it does. Would drive it around but it is currently bedless and needing the rear tank fixed. I can't thank you guys enough for all your help. I'll keep you posted on how it does.